I was trying to launch Maestro on a remote machine and display it locally via ssh with X forwarding, when this error came up. What do I do?

Verify that you are connecting to the remote machine via ssh with X forwarding, e.g.:

ssh remotemachine -X

If you use the -X option, the display should automatically be set up. If it is not,
then once you are connected to remotemachine and after setting the SCHRODINGER environment variable, please try setting the DISPLAY environment variable to localmachine:0 before launching Maestro.